Prepregnancy extreme obesity is associated with increased steroid dispensing in early childhood

Prepregnancy overweight and obesity have been linked to early childhood wheezing and asthma, but the presence and strength of such associations are mixed and the underlying biological mechanisms remain poorly elucidated. Wheezing is common in young children and rigorous measures of child respiratory health are critical to evaluating the relationship between maternal weight and offspring respiratory health. We compared maternal body mass index [BMI (kg/m²)] at pregnancy onset with steroid dispensing in offspring through 4 years of age in a sample of women and children receiving care through Kaiser Permanente Northwest (KPNW). Data were abstracted from KPNW medical records of healthy full-term infants (≥37 gestational weeks). Maternal BMI was categorized by 5 groups from underweight (<18.5 kg/m²) to extreme obesity (≥40 kg/m²) with normal BMI (18.5-24.9 kg/m²) as the referent. The relationship between prepregnancy BMI and steroid dispensing through 4 years of age was examined using logistic regression modeling. Of the 6,194 pregnancies in our study sample, 20% were affected by obesity (BMI 30-39.9 kg/m²) and 5% by extreme obesity. Maternal and infant characteristics were significantly different across all BMI categories. Adjusting for significant covariates, we found that children of mothers with extreme obesity were at increased odds of steroid dispensing (odds ratio 1.43; 95% confidence interval 1.05-1.96) compared with the referent. Maternal asthma increased in a stepwise manner with BMI category and diminished the strength of the association between maternal BMI and steroid dispensing to offspring. We observed a statistically significant relationship between steroid dispensing to offspring and extreme prepregnancy obesity. It is unclear whether maternal asthma is on the causal pathway between maternal BMI and offspring steroid dispensing, a confounder of the relationship, or both. Further research should focus on disentangling the influence of maternal asthma on this proposed relationship.